1. Field of the Invention
This invention relates to laser systems. More specifically, this invention relates to improvements in the pumping of lasers which may be excited by light emitting diodes and diode lasers.
While the present invention is described herein with reference to a particular application, it should be understood that the invention is not limited thereto. The teachings of the present invention may be adapted and employed for a variety of requirements as those skilled in the art will recognize in light of the present disclosure.
2. Description of the Prior Art
A diode-pumped neodymium yttrium alluminum garnet (hereafter Nd:YAG) laser is under consideration for use in space optical communications because it offers the advantages of compactness and efficiency while not requiring the power supply of an excitation lamp or the solar tracking optical assembly of a typical solar pumping scheme. The light-emitting diode and the injection laser diode both offer a high brightness, wavelength selectable source which may be efficiently coupled to the absorption bands of the Nd:YAG laser. Although considerable progress has been made in the growth of high quality luminescent diode materials, the maximum power efficiency for either is currently 6 to 15 percent. Unfortunately, the output power currently available from these devices is low. In addition, thermal limitations arise from the high power density in the diodes which in turn places a limit on the number of devices that can be mounted on or near the laser cavity for such pumping. Thus, a limitation on the applicability of diode pump Nd:YAG lasers to space optical communications arises from the problem of providing sufficient optical power from the pumping diodes to the laser rod.